scratchbuild E-savage derived RB3
 

First real adventure in terms of an all aftermarket build. Built from parts from HPI, GCM, Panic Toys, Kershaw and a couple others.

Truck is an RB3, an E-savage derivative built primarily for racing. Main conversion is from GCM. Truck is pretty interesting in being an electronics AND tranny forward truck allowing a sort of pick up bed in the rear of the chassis for internally mounting the lipos. Drivetrain is all steel/alloy apart from the gears in the center tranny which are the stock tough plastic e-savage ones. Center driveshafts are quite possibly the stoutest I've ever seen. Servo is mounted outside the chassis to allow room for spur and steering components and has the happy side effect of keeping the servo cool. That Ace does get pretty hot turning LPRs. Truck is almost entirely cnc'd anodised black and red alloy, exceptions being bulkheads, center tranny cases, hubs and upper arms, which are delrin for lightness.

Truck is designed to be light as possible. Running 3s through a 3000kv ish motor and a mamba max. All up weight of the GCM development truck including wheels and tires, lipo, radio and motor was 3.7 kilos.

http://img39.imageshack.us/img39/1296/dscf0028y.jpg

http://img443.imageshack.us/img443/2391/dscf0032g.jpg

http://img443.imageshack.us/img443/305/dscf0047f.jpg

http://img442.imageshack.us/img442/7079/dscf0043.jpg

Sounds good but the pic links are broken.

Pics fixed, my bad. Was in a rush to get out the door lol.

Couple more bits about the truck, CVDs are RDlogic, diffs use e-savage ring gears and pinions but run an alloy case and modified internals for better mesh and reliability. Motor mount is a custom cut and finished item from Chris at GCM. Truck is presently running original E-savage shocks meant for the tall plastic towers. This truck is fitted with the RB3 specific short towers so a set of good quality truggy shocks will be going on it when i get some cash. For reference, it doesn't look it but the truck is the same width as a Flux and about a centimetre shorter, so it's pretty big for it's weight.

I need help figuring a motor, was going to plump for a 3100 60 v2 Medusa, but thats gone up the swanny now. Will be running 4s in this, through a Mamba Max Pro when it comes out. Truck won't be very heavy and drivetrain is very free. Spur is a 66t and gearing is presently mod .8/32p.

Looking for something around 3000kv, not a feigao. The rest of the truck is rather trick, don't want to phone it in on the motor. Anyone got any ideas?

Neu 1509/1512?

Hmm, CastleNeu 2650kv? Or perhaps a 1512 2D Neu (2550kv)?

Tekin has lots of motors now, shorter and longer varients in a few kv flavours.

The truck itself is pretty sweet looking- looks alot smaller than it actually is (got anything for comparison?).

Red & black colourscheme is very sharp too.

Slapped a Revo 3.3 shell and some dirt bonz on it to give an idea. It's a wierd kind of big, like a dog with a big furry coat. Shave it off and there's a little lanky thing underneath it all lol. It's got a big wheelbase and is pretty wide but has a narrow chassis and not much in the way of bumpers.

http://img19.imageshack.us/img19/4492/dscf0053arx.jpg

I've ordered a Turnigy 4s 30c-40c pack for it as according to the hit and miss sizes on hobbycity it should fit pretty well. Also picked up a cheapy 3000kv inrunner just to get it rolling. Will attempt to source a Neu at some point, A 1512 should be just about right I reckon. God dang expensive though.

The CastleNeu 2650kv is 1512 sized, and puts out pretty much the same amount of power- only real difference is the finned can vs smooth you can get with the neus (green colour scheme may be an issue too...). Alot cheaper is my main thought.

I get you on the size thing, savys are rather slender under the shell, but with a shell & wheels its a lot more impossing. Me likes.. :yes:

Sounds like that may well be the way to go then, what sort of length is a 1512? I'm kind of limited in this application. Too long and it starts cutting into the lipo room, having said that the Turnigy Lipo is apparently only 35ish mm high so any motor should be able to fit over the top of it as the lipo bay is 36mm deep.

Yeah, it's kind of wierd. I just sat the Revo next to the RB3 and the wheelbase is pretty much the same, the width hex to hex is similar, the bumpers are about an inch off, but the Revo looks huge compared to it. I guess it's because the Revo is so cluttered and a bit of a messy ungainly design. The RB3 is perfect to me, cut right back to the basic requirements... One of the reasons I always refused to buy a factory conversion (E-revo, Savage Flux etc.) was because I knew that a porky nitro with a few changes and an electric motor lobbed in there wasn't really doing the sheer power and advanced technology of electric the justice it deserves. There is no way an E-revo should weigh over 5 kilos even with packs.

I got annoyed with the lazyness of manufacturers not giving these fantastic power systems the platform they deserve in a bespoke, ground up designed electric truck. It's kind of like finding the worlds greatest race horse, then finding the worlds fattest jockey to ride it. I looked around a bit and found the RB3, looked it over and watched the development videos of it pulling a standing backflip with a mamba max, 3s lipo and a medusa 50mm can motor, half the brushless system in a Flux, and was hooked. Just ca $900 later i had the rolling chassis with all the bits I wanted lol. Never said it was gonna be cheap.

Specs

68mm long, so not too bad.

$900 is cheap by my standards :lol: , but then being lightweight and compact isnt a concern- bashing a shelf queen thats near bullet proof & sturdy is more than enough fun for me.

If I take the lower battery plate off my GorillaMaxx, it suddenly looks alot slimmer, its just the servo mounts up front that make it look a bit fatter- you could do alot with the chassis design + keep the front and rear bulks...

Haha, $900 is pretty pricey to me, particularly when customs shove the price up over the $1000 mark just for the chassis. By the time I get the truggy shocks, esc, bodyshell, digi receiver, motor, wheels and tyres and lipos it's easily going to be a $1800+ build.

Hmmm 68mm is pushing it, I think I'll wait till the lipos get here to see how much room I'm gonna have left. I know they use the full length of the battery tray so if they are tall enough to stick out the top of the tray i'll be limited to 60mm motors.

Your setup is probably newer, but have you seen this? http://www.rcuniverse.com/forum/fb.asp?m=8720738

Might give you some ideas for your setup.


Anyway, awesome setup, looks like it would be a lot of fun to drive!

go with a tekin berushless system- red and black and killer

That's a simply beautiful E-Savage!

Are you going to run 3s or 4s? In your first post, you said 3s. Then later, you said 4s.
If you're running 4s, I wouldn't recommend a 3000kV motor or anything near it. If 3s, then you're fine.
If you're running 3s (which is really enough for that truck), a Tekin T8 4030 motor would be great. Or as already mentioned, the CC/Neu 2650kV motor. Tekno also has their Lektron motors that are about 60mm long, which might fit perfectly in your E-Sav. The Lektrons also have built-in mounts for 40mm fans.
If all else fails and you can't find something you like, I have a Medusa 3300kV 3650 motor I don't use (just got it today).

BTW, are you on E-Savage.com?

Ah, I follow Banx's truck on E-savage.com. It's a true out and out MT racer. He has the RB2 chassis though, it's quite a bit different to the RB3 (which incidentally, came before the RB2) The model designations don't indicate a progression, more just different code names for different projects. The RB2 is more aimed at being the ultimate E-savage chassis, rather than changing the truck completely like the RB3.

JSR: I plan to run both 4s and 3s, 3s for race, 4s for bashing. I plan on getting the CC/Neu 2650 for 4s running. If you are willing to part with that Medusa give me a private message with what you want for it, that motor is perfect for 3s running in this thing.

Yeah, I'm on E-sav.com, I'm lilredmachine on there. Reminds me, must post progress over there!

Tekin eh? I've heard much about them but never owned any of their stuff.

Worth also looking at the motors Linc has for sale, lots of Aveox items that are same quality as Neu, and some smaller can lengths to fit your truck- 36/30/1.5 (1512, 2000kv) on 4s lipo would be potent, but a bit slow for 3s. Depends if you were thinking of one motor for both voltages, or swapping them out depending on what you were doing..